1. Field of the Invention
The present invention relates to a micro-magnetization analysis program, method, and apparatus for analyzing a state or change of micro-magnetization of magnetic substances of micron- or nano-order regions; and, particularly relates to a micro-magnetization analysis program, method, and apparatus for analyzing micro-magnetization by using the finite element method and the boundary element method in discretization of two magnetic substances which move relative to each other with respect to, for example, writing or reading of a magnetic head of a hard disk, using the finite volume method in discretization of an LLG equation describing motion of the micro-magnetization, and providing simultaneous equations thereof.
2. Description of the Related Arts
Conventionally, as a micro-magnetization analysis program and analysis apparatus in which, for example, a recording head and a recording medium of a hard disk serve as magnetic substance models, the analysis object model is subjected to mesh-division into minute elements, parameters (unknown values) of micro-magnetization vectors are allocated to the center of the minute elements, and the magnet field distribution of the entire region is calculated by use of the LLG (Landau-Lifshitz-Gilbert) equation as a magnetic field equation. It is an equation which describes motion of micro-magnetization (small magnets) in a magnetic field; and, in the first place, as shown in FIG. 1A, all the regions of a magnetic substance region corresponding to a recording medium 202, a magnetic substance region constituting a recording head 204, a magnetic substance region corresponding to a coil 208, and an air region 210 surrounding the magnetic substance regions in an analysis object model 200 are subjected to mesh-division into minute elements of, for example, several tens to several hundreds nm order. Subsequently, as shown in FIG. 1B, with respect to all of the magnetic substance regions and the air regions 210, vector potentials 214 which are unknown values of equations of the magnetic fields are disposed on sides of mesh-divided minute elements 212, and equations of steady magnetic fields or unsteady magnetic fields are solved by the finite element method. Subsequently, as shown in FIG. 1C, with respect to a micro-magnetization region 206 of FIG. 1A which is treated as micro-magnetization for generating a recording magnetic field, micro-magnetization 216 which is an unknown value M of the LLG equation is disposed at the center of the minute element 212, and the equation of the magnetic field and the LLG equation are alternately solved, thereby calculating a micro-magnetization state for a recording operation of the micro-magnetization region 206.
However, in such conventional magnetic analysis of micro-magnetization regions, since merely the finite element method is used for the equations of the magnetic field, all the magnetic substance regions including the air regions 210 have to be subjected to mesh division, and unknown values of the equations of the magnetic field have to be disposed in all the minute elements. Therefore, minute elements caused by mesh division are present also in the air regions 210 between the magnetic substance regions of the recording medium 202 and the magnetic substance regions constituting the recording head 204, thereby leading to a problem that numerical analysis of the magnetization state during a recording process cannot be performed while the magnetic substance regions of the recording medium 202 are moved. If the magnetic substance regions of the recording medium 202 which moves are modeled and analyzed, as shown in FIGS. 2A to 2C, a plurality of models 200-1 to 200-3 has to be generated and used, and man-hours of analysis processing increases and processing takes time. In addition, when air regions between magnetic substance regions are to be subjected to mesh-division to generate minute elements in the conventional manner, continuity of the minute elements has to be maintained; therefore, it is difficult to generate a magnetic region having a simple shape such as a recording medium as a model in the vicinity of a magnetic substance region having a complex shape such as a recording head. Furthermore, there is also a problem that, along with movement of the magnetic substance region of the recording medium 202, the mesh shape of the air region 210 between the region and the magnetic substance region of the recording head 204 side is deformed from an initially set rectangle to a trapezoid, and this deformation of the mesh lowers the calculation accuracy.